Variability and correlation of physical attributes of soils cultivated with cacao trees in two climate zones in Southern Bahia, Brazil

Abstract

Cacao (Theobroma cacao) is a very important crop in Southern Bahia, Brazil, which needs good climate and soil conditions and management for great productivity. In this region, cacao is grown on a large number of soil types, and soil properties have great effects on its sustainability and production potentials. The aim of this study was to evaluate the variability of physical attributes of soils cultivated with cacao in two climate zones in Southern Bahia, Brazil, as well as to evaluate the correlation between these physical attributes. Eighty soil samples were evaluated from 20 cacao farms with cacao agroforestry systems, from the 0–0.1 and 0.1–0.3 m soil layers. The soil analyses comprised granulometry, soil bulk density, particle density, porosity (total, macro, and micro), gravimetric moisture, and soil resistance to penetration. The data were submitted to descriptive statistical analysis and correlation between variables. Most variables had normal distribution (p > 0.05) and high variability. In general, these soils had good physical conditions for the production of cacao, except for the high resistance to root penetration which can be limiting factor. The greatest differences in physical attributes of the soils were: gravimetric moisture, resistance to penetration, macroporosity, and sand content. The correlations between physical attributes of the soils varied according to the sampled layer and the climate zone. The resistance to penetration was not correlated with any of the determined physical attribute.